Summoning sciences?

In the Mages Tower during the summoning sciences quest,I have done the first,second and third summoning exercises yet if you,from that library-like room just after meeting wynne,go into the next room[the circular room with a table in the middle and bookcases around the walls]one of the bookcases has fallen and you can walk around behind it.Back there if you have activated the summoning font is another red thing called 'Summoning the Fourth' yet the codex on Summoning Sciences has no mention of a fourth exercise and the quest is marked as finished in my quest log.Is there a secret part to the quest or is it just nothing?

Accepted Answer

Fourth summons is an Easter Egg. Do all the steps of the first three summons (without touching the fonts) and then touch the fourth font. Have a pickpocket ready to go and pickpocket the "Arl Foreshadow" that appears to get a codex entry. You can read about it here: